1 /* Test file for mpfr_ui_div.
2
3 Copyright 2000-2023 Free Software Foundation, Inc.
4 Contributed by the AriC and Caramba projects, INRIA.
5
6 This file is part of the GNU MPFR Library.
7
8 The GNU MPFR Library is free software; you can redistribute it and/or modify
9 it under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or (at your
11 option) any later version.
12
13 The GNU MPFR Library is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
15 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
16 License for more details.
17
18 You should have received a copy of the GNU Lesser General Public License
19 along with the GNU MPFR Library; see the file COPYING.LESSER. If not, see
20 https://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
21 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
22
23 #include "mpfr-test.h"
24
25 /* checks that y/x gives the right result with 53 bits of precision */
26 static void
27 check (unsigned long y, const char *xs, mpfr_rnd_t rnd_mode, const char *zs)
28 {
29 mpfr_t xx, zz;
30
31 mpfr_inits2 (53, xx, zz, (mpfr_ptr) 0);
32 mpfr_set_str1 (xx, xs);
33 mpfr_ui_div (zz, y, xx, rnd_mode);
34 if (mpfr_cmp_str1(zz, zs))
35 {
36 printf ("expected quotient is %s, got ", zs);
37 mpfr_out_str (stdout, 10, 0, zz, MPFR_RNDN);
38 printf ("mpfr_ui_div failed for y=%lu x=%s with rnd_mode=%s\n",
39 y, xs, mpfr_print_rnd_mode (rnd_mode));
40 exit (1);
41 }
42 mpfr_clears (xx, zz, (mpfr_ptr) 0);
43 }
44
45 static void
46 check_inexact (void)
47 {
48 mpfr_t x, y, z;
49 mpfr_prec_t px, py;
50 int inexact, cmp;
51 unsigned long int u;
52 int rnd;
53
54 mpfr_init (x);
55 mpfr_init (y);
56 mpfr_init (z);
57
58 for (px = MPFR_PREC_MIN; px < 300; px++)
59 {
60 mpfr_set_prec (x, px);
61 do
62 {
63 mpfr_urandomb (x, RANDS);
64 }
65 while (mpfr_cmp_ui (x, 0) == 0);
66 u = randlimb ();
67 for (py = MPFR_PREC_MIN; py < 300; py++)
68 {
69 mpfr_set_prec (y, py);
70 mpfr_set_prec (z, py + px);
71 RND_LOOP (rnd)
72 {
73 inexact = mpfr_ui_div (y, u, x, (mpfr_rnd_t) rnd);
74 if (mpfr_mul (z, y, x, (mpfr_rnd_t) rnd))
75 {
76 printf ("z <- y * x should be exact\n");
77 exit (1);
78 }
79 cmp = mpfr_cmp_ui (z, u);
80 if (rnd != MPFR_RNDF && ! SAME_SIGN (inexact, cmp))
81 {
82 printf ("Wrong inexact flag for u=%lu, rnd=%s\n",
83 u, mpfr_print_rnd_mode ((mpfr_rnd_t) rnd));
84 printf ("expected %d, got %d\n", cmp, inexact);
85 printf ("x = "); mpfr_dump (x);
86 printf ("y = "); mpfr_dump (y);
87 printf ("y*x = "); mpfr_dump (z);
88 exit (1);
89 }
90 }
91 }
92 }
93
94 mpfr_clear (x);
95 mpfr_clear (y);
96 mpfr_clear (z);
97 }
98
99 static void
100 check_special (void)
101 {
102 mpfr_t d, q;
103
104 mpfr_init2 (d, 100L);
105 mpfr_init2 (q, 100L);
106
107 /* 1/+inf == +0 */
108 MPFR_SET_INF (d);
109 MPFR_SET_POS (d);
110 mpfr_clear_flags ();
111 MPFR_ASSERTN (mpfr_ui_div (q, 1L, d, MPFR_RNDZ) == 0); /* exact */
112 MPFR_ASSERTN (MPFR_IS_ZERO (q) && MPFR_IS_POS (q));
113 MPFR_ASSERTN (__gmpfr_flags == 0);
114
115 /* 1/-inf == -0 */
116 MPFR_SET_INF (d);
117 MPFR_SET_NEG (d);
118 mpfr_clear_flags ();
119 MPFR_ASSERTN (mpfr_ui_div (q, 1L, d, MPFR_RNDZ) == 0); /* exact */
120 MPFR_ASSERTN (MPFR_IS_ZERO (q) && MPFR_IS_NEG (q));
121 MPFR_ASSERTN (__gmpfr_flags == 0);
122
123 /* 1/nan == nan */
124 MPFR_SET_NAN (d);
125 mpfr_clear_flags ();
126 MPFR_ASSERTN (mpfr_ui_div (q, 1L, d, MPFR_RNDZ) == 0); /* exact */
127 MPFR_ASSERTN (mpfr_nan_p (q));
128 MPFR_ASSERTN (__gmpfr_flags == MPFR_FLAGS_NAN);
129
130 /* 0/0 == nan */
131 mpfr_set_ui (d, 0L, MPFR_RNDN);
132 mpfr_clear_flags ();
133 MPFR_ASSERTN (mpfr_ui_div (q, 0L, d, MPFR_RNDZ) == 0); /* exact */
134 MPFR_ASSERTN (mpfr_nan_p (q));
135 MPFR_ASSERTN (__gmpfr_flags == MPFR_FLAGS_NAN);
136
137 /* 1/+0 = +inf */
138 mpfr_set_ui (d, 0L, MPFR_RNDN);
139 mpfr_clear_flags ();
140 MPFR_ASSERTN (mpfr_ui_div (q, 1L, d, MPFR_RNDZ) == 0); /* exact */
141 MPFR_ASSERTN (mpfr_inf_p (q) && mpfr_sgn (q) > 0);
142 MPFR_ASSERTN (__gmpfr_flags == MPFR_FLAGS_DIVBY0);
143
144 /* 1/-0 = -inf */
145 mpfr_set_ui (d, 0L, MPFR_RNDN);
146 mpfr_neg (d, d, MPFR_RNDN);
147 mpfr_clear_flags ();
148 MPFR_ASSERTN (mpfr_ui_div (q, 1L, d, MPFR_RNDZ) == 0); /* exact */
149 MPFR_ASSERTN (mpfr_inf_p (q) && mpfr_sgn (q) < 0);
150 MPFR_ASSERTN (__gmpfr_flags == MPFR_FLAGS_DIVBY0);
151
152 /* 0/1 = +0 */
153 mpfr_set_ui (d, 1L, MPFR_RNDN);
154 mpfr_clear_flags ();
155 MPFR_ASSERTN (mpfr_ui_div (q, 0L, d, MPFR_RNDZ) == 0); /* exact */
156 MPFR_ASSERTN (MPFR_IS_ZERO (q) && MPFR_IS_POS (q));
157 MPFR_ASSERTN (__gmpfr_flags == 0);
158
159 /* 0/-1 = -0 */
160 mpfr_set_si (d, -1, MPFR_RNDN);
161 mpfr_clear_flags ();
162 MPFR_ASSERTN (mpfr_ui_div (q, 0L, d, MPFR_RNDZ) == 0); /* exact */
163 MPFR_ASSERTN (MPFR_IS_ZERO (q) && MPFR_IS_NEG (q));
164 MPFR_ASSERTN (__gmpfr_flags == 0);
165
166 mpfr_clear (d);
167 mpfr_clear (q);
168 }
169
170 static int
171 mpfr_inv (mpfr_ptr y, mpfr_srcptr x, mpfr_rnd_t r)
172 {
173 return mpfr_ui_div (y, 1, x, r);
174 }
175
176 static void
177 check_overflow (void)
178 {
179 mpfr_exp_t emin, emax;
180 mpfr_t x, y1, y2;
181 int inex1, inex2, rnd_mode;
182 mpfr_flags_t flags1, flags2;
183
184 emin = mpfr_get_emin ();
185 emax = mpfr_get_emax ();
186 set_emin (MPFR_EMIN_MIN);
187 set_emax (MPFR_EMAX_MAX);
188
189 mpfr_inits2 (32, x, y1, y2, (mpfr_ptr) 0);
190 mpfr_setmin (x, MPFR_EMIN_MIN);
191 RND_LOOP (rnd_mode)
192 {
193 inex1 = mpfr_overflow (y1, (mpfr_rnd_t) rnd_mode, 1);
194 flags1 = MPFR_FLAGS_OVERFLOW | MPFR_FLAGS_INEXACT;
195 mpfr_clear_flags ();
196 inex2 = mpfr_ui_div (y2, 1, x, (mpfr_rnd_t) rnd_mode);
197 flags2 = __gmpfr_flags;
198 if (!(mpfr_equal_p (y1, y2) &&
199 SAME_SIGN (inex1, inex2) &&
200 flags1 == flags2))
201 {
202 printf ("Error in check_overflow for %s\n",
203 mpfr_print_rnd_mode ((mpfr_rnd_t) rnd_mode));
204 printf ("Expected ");
205 mpfr_dump (y1);
206 printf (" with inex = %d, flags =", inex1);
207 flags_out (flags1);
208 printf ("Got ");
209 mpfr_dump (y2);
210 printf (" with inex = %d, flags =", inex2);
211 flags_out (flags2);
212 exit (1);
213 }
214 }
215 mpfr_clears (x, y1, y2, (mpfr_ptr) 0);
216
217 set_emin (emin);
218 set_emax (emax);
219 }
220
221 #define TEST_FUNCTION mpfr_ui_div
222 #define ULONG_ARG1
223 #define RAND_FUNCTION(x) mpfr_random2(x, MPFR_LIMB_SIZE (x), 1, RANDS)
224 #include "tgeneric.c"
225
226 int
227 main (int argc, char *argv[])
228 {
229 tests_start_mpfr ();
230
231 check_special ();
232 check_inexact ();
233 check(948002822, "1.22191250737771397120e+20", MPFR_RNDN,
234 "7.758352715731357946e-12");
235 check(1976245324, "1.25296395864546893357e+232", MPFR_RNDZ,
236 "1.5772563211925444801e-223");
237 check(740454110, "2.11496253355831863313e+183", MPFR_RNDZ,
238 "3.5010270784996976041e-175");
239 check(1690540942, "1.28278599852446657468e-276", MPFR_RNDU,
240 "1.3178666932321966062e285");
241 check(1476599377, "-2.14191393656148625995e+305", MPFR_RNDD,
242 "-6.8938315017943889615e-297");
243 check_overflow ();
244
245 test_generic (MPFR_PREC_MIN, 1000, 100);
246
247 /* inv is for 1/x */
248 data_check ("data/inv", mpfr_inv, "mpfr_ui_div(1,x)");
249
250 tests_end_mpfr ();
251 return 0;
252 }